The present invention relates to an apparatus for continuous processing in the directions of x- and y-coordinates, suitably especially for soldering a work piece such as a semiconductor device, for example and IC-chip, an LSI-chip or the like, on a substrate plate, wherein the distance between a pair of parallel linear sections to be processed (processing lines) and the length of the processing line are different in the directions of the x- and y-coordinates.
For soldering terminal pins of semiconductor devices, such as IC-chips and LSI-chips, to those of a substrate, there have been in practical use non-contact type apparatuses, in which a laser beam transmitted through a flexible light conducting filament (optical fiber) is employed to provide spot irradiation at the soldering site to attain soldering of each lead pin of the semiconductor chip with a corresponding pin of the substrate, and contact-type apparatuses, in which the soldering is effected by the use of a soldering iron directly contacting the soldering spot.
The non-contact type soldering apparatuses are costly, since high price optical elements and devices are required, such as optical fibers, etc. The irradiation of the soldering spot by a laser beam may sometimes accidentally burn the substrate or destroy the semiconductor chip during the processing operation by the high temperature resulting from the laser beam.
A non-contact type soldering apparatus may sometimes produce a defective connection at the processed site, because of the flux material, contaminants adhering to the soldering iron, and so on, so that it is necessary to remove the contaminants and to polish the soldering iron tip at frequent intervals. In particular, it has been necessary to change or replace the soldering iron tip in accordance with the alteration of the type and form of the semiconductor chip to be processed. This makes it necessary to stock various types of soldering iron tip. In addition, in the case of contact type apparatuses, a continuous processing in the directions of the x- and y-coordinates is not possible, when the distance between the processing lines or the length thereof is different in the directions of x- and y-coordinates, since it is necessary to let the iron tip contact each processing site.
The inventors have conducted extensive research to develop an apparatus capable of realizing a high processing performance without connection failure in an economical manner, taking into account the fact that non-contact type soldering produces cleaner work with higher efficiency than contact-type soldering; and in this way the inventors have reached the present invention.